The present invention relates to an article supply device and an automatic assembly apparatus for assembling a plurality of parts into a predetermined article supplied by the supply device while conveying a robot on a movable shuttle.
In a conventional automatic assembly apparatus, as disclosed in Japanese Patent Publication No. 63-33972, a large number of parts supply mechanisms for supplying a large number of parts to one robot are arranged around the robot. As an interlocking signal in operation control of the robot, a parts preparation end signal, and the like of each parts supply mechanism must be transmitted to a control mechanism of the robot. For this reason, in the conventional apparatus, the parts supply mechanisms are electrically connected to the control mechanism through connection cables to perform signal communications.
As described in an article supply device (U.S. Pat. No. 4,844,680) according to the prior application of the present applicant, a system wherein parts supply shelves are used to supply a large number of parts to a robot, a pallet storing necessary parts is drawn out from these parts supply shelves, and the robot accesses this pallet to pick up a necessary part, is known. In the conventional automatic assembly apparatus, in order to introduce a camera as a visual device for electrically checking parts alignment states in the pallets, the camera must be arranged above the pallet drawn out from the parts supply shelves.
A technique of causing a traveling robot to access a large number of parts, thereby picking them up as disclosed in Japanese Patent Publication No. 63-33972 described above is known. This patent publication also describes that a parts supply mechanism which integrally travels in synchronism with travel of the robot is adopted.
Since the conventional automatic assembly apparatus deals with a large number of parts, the number of parts supply mechanisms is increased. Thus, when the parts supply mechanisms are connected to the control mechanism of the robot through connection cables to communicate with it, the problems to be described below are posed.
That is,
(1) When an automatic assembly apparatus is manufactured (arranged), the number of assembly steps (e.g., wiring) is increased, and cost of wiring (i.e., labor cost and cost of wiring materials) is considerable.
(2) Since the number of wirings is increased, a wiring error easily occurs.
(3) A sequence of the control mechanism of the robot requires input ports corresponding in number to the number of parts supply mechanisms. The increase in the number of ports causes an increase in cost of the sequence. When the number of objective parts is increased, the ports of the sequence become short, and the increase in the number of parts cannot be coped with.